Pumping unit having flow directing means



Nov. 19, 1957 T. J. DESKA 2,813,488

PUMPING UNIT HAVING FLOW DIRECTING MEANS Filed Sept. 50, 1953 2Sheets-Sheet 1 25 56. 4 INVENTOR.

F'J MEODORE figs ATTOENE 5 Nov. 19, 1957 T. J. DESKA 2,813,433

PUMPING UNIT HAVING FLOW DIRECTING MEANS Filed Sept. so, 1953 2Sheets-Sheet z INVENTOR. lira-came J. 065/(4 FIG-8 BY Arrow/vs s PUMPINGUNIT HAVING FLOW DIRECTING MEANS Theodore J. Deska, Detroit, Mich.,assignor to Eaton Manufacturing Company, Cleveland, Qiiio, a corporationof Ohio Application September 30, 1953, Serial No. 383,318

Claims. (Cl. 10342) This invention relates to rotary pumps and pumpingunits of the positive displacement type adapted to be driven by avehicle engine for supplying actuating fluid under pressure to ahydraulic power steering motor or other auxiliary device to be actuated.

This application is related, as to subject matter and ownership, toearlier application Serial No. 261,654, filed December 14, 1951, nowPatent 2,724,335, granted November 22, 1955.

A rotary pump being driven and used in this manner is subject tooperation at widely varying speeds. The out put capacity of the pumpmust be suflicient to meet the requirements of the auxiliary deviceduring low speed operation of the vehicle, and accordingly, the pressureand volume values of the pump delivery during high speed operation ofthe vehicle are usually considerably in excess of the requirements or"the auxiliary device.

The auxiliary device is usually contained in a closedloop externalcircuit through which fluid is forced by the pump and the excess fluidis by-passed from the discharge side of the pump to the intake sidethereof. The present invention is particularly concerned with theby-passing of this excess fluid and, as one of its objects, aims toprovide a rotary pump having novel flow directing means by which theby-passed fluid is returned to the intake side of the pump with minimumturbulence and noise.

Another object is to provide a rotary pump having novel flow directingmeans by which the by-passed fluid is returned to the intake side in amanner such that the velocity and direction of the stream of by-passedfluid will assist the flow of intake fluid toward the intake port of thepump and such that the energy of the high Velocity fluid will beutilized in increasing the pressure head of the fluid in the intake atpoints downstream from the junction point of the stream of by-passedfluid with the stream of intake fluid.

Still another object is to provide a rotary pump having novel flowdirecting means for the purpose mentioned above and which comprisesdeflector means located in the intake passage and substantially oppositea junction port connecting the by-pass passage with the intake passage.

A further object is to provide a rotary pump with a flow directing meansof the kind above indicated and comprising an insert sleeve extendingalong the intake passage and having a fluted portion defining suchdeflector means.

The invention can be further briefly summarized as consisting in certainnovel combinations and arrangements of parts hereinafter described andmore particularly set out in the claims hereof.

In the accompanying sheets of drawings, forming a part of thisspecification:

Fig. l is mainly an end elevation of a pumping unit embodying thisinvention, but with portions of the unit broken away;

Fig. 2 is a partial vertical axial section taken through 2,813,438Patented Nov. 19, 1957 bypass valve means;

Fig. 5 is a partial transverse vertical section taken on section line 55of Fig. 2 and showing the rotor chamber and the gear type rotorstherein;

Fig. 6 is an elevational view showing the flow directing insert in adetached relation;

Fig. 7 is an end view of the insert; and

Fig. 8 is a sectional view taken through the insert longitudinallythereof on section line 88 of Fig. 7.

The rotary pump 10 which will be presently described in detail is shownin the drawings as forming a part of a pumping unit 11 which supplieshydraulic fluid under pressure to a closed-loop external fluid circuit12. The external fluid circuit 12 includes an auxiliary or accessorydevice which is operated by the hydraulic pressure being supplied by thepump 10 and may be a hydraulic power steering device 13 which is hereshown only diagrammatically. The external fluid circuit also includesdelivery and return conduit members or fittings 14 and 15 by which therotary pump 10 is operably connected with such circuit.

The pumping unit 11 also includes a reservoir member 16 which is mountedon and supported directly by the rotary pump 10 and defines a reservoirchamber 17 adapted to contain a quantity of the hydraulic fluid. Afitting 18 extending into the reservoir 16 has an axial passage 19through which fluid being returned from the external circuit 12 isdirected into the reservoir chamber 17. The fitting 18 also forms asupport for a substantially cylindrical strainer 20 which is disposedaround this fitting and through which the returned fluid must pass inflowing into the reservoir chamber.

The rotary pump 10 is provided with a pump housing 22 which is formed bya pair of connected housing sections 22 and 22 The housing section 22*comprises a body member having a rotor chamber 23 therein. This hous ingsection 22 is also provided with a pair of arcuately extending intakeand discharge ports 24 and 25 which communicate with the rotor chamber23 at one end thereof. The discharge port 25 is in the form of anarcuate pocket which can be conveniently referred to as a blind pocketinasmuch as this pocket does not have any intake or discharge passageconnected therewith but communicates only with the pumping chambers 35.The housing section 22 forms a cover for the rotor chamber 23 andcontains a pair of arcuately extending intake and discharge ports 26 and27 which communicate with the rotor chamber 23 at the opposite endthereof.

As shown in the drawings, the rotary pump 10 also includes a shaft 28having its outer end rotatably sup ported in the housing section 22 by abushing 29 mounted in the latter. The inner end of the shaft 28 isrotatably supported by a bushing 30 mounted in the housing section 22 Asshown in Fig. 2, the inner end of the shaft projects beyond the bushing30 and also extends through an annular packing 31 which is mounted inthe housing section 22 adjacent the bushing. The inner end of the shaft28 is adapted for connection with an available rotating part from whichthe rotary pump is to be driven. The housing section 22 is provided witha flange 32 adapted for connection with an available support on whichthe rotary pump 10 is to be mounted.

The pump 1b also includes rotor means operable in the rotor chamber 23for producing a pumping action and which rotor means comprises a pair ofouter and inner rotor members 33 and 34. These rotor members port 27through a connecting passage 42.

chamber 39 defines a dash pot cylinder 44.

have toothed portions in cooperating meshing engagement for definingvariable pumping chambers 35 therebetween and whch pumping chambers comeinto communication with the intake and discharge ports in succession.The outer rotor member 33 is rotatably supported by a cylindrical lineror bushing 36 mounted in the rotor chamber 23. The inner rotor member 34is mounted on the shaft 23 and is connected therewith by the key 37.

The housing section 22* is provided with an intake passage 38 extendingin depending relation from the reservoir chamber 17 and which connectsthe reservoir chamber with the intake port 24. The housing section 22 isalso provided with a return fluid passage 15 which connects the returnconduit 15 of the external fluid circuit with the passage 19 leadinginto the reservoir chamber 17. The housing section 22 contains a valvechamber 39 which extends in spanning relation to the intake anddischarge ports 26 and 27 of this housing member and which contains asuitable bypass valve means, such as the valve assembly 46 here shownand which will be further described presently.

As shown in Fig. 4, the valve chamber 39 is provided at an intermediatepoint thereof with an internal annular valve seat 41. inwardly of thevalve seat 41 this valve chamber is in communication with the dischargeA portion 39 of this valve chamber which is located outwardly of thevalve seat 41, is in communication with a bypass passage 43 throughwhich by-passed fluid is returned to the intake side of the pump in amanner to be explained hereinafter. The extreme inner end portion of thevalve The extreme outer end portion of the valve chamber 39 defines aspring chamber and delivery passage 45 through which the pumped fluidbeing supplied to the external fluid circuit 12 is delivered. The outerend of the valve chamber is closed by the fitting or conduit member 14which has a passage 14 therein connecting the delivery passage 45 withthe external fluid circuit.

The valve assembly 40 is operable in the valve chamber 39 as a by-passvalve means which controls the flow of by-passed fluid from the valvechamber through the passage 43. This valve assembly comprises a volumecontrol valve member 46 and a pressure relief valve member 47. Thevolume control valve member 46 is a hollow valve member having an axialpassage 48 therein and also having radial ports 49 through which theaxial passage is connected with the discharge port 27. At anintermediate point thereof, the valve member 46 is provided with a valveplunger portion which cooperates with the valve seat 41. At its innerend, the valve member 46 is provided with a dash pot plunger 51 which isoperable in the dash pot cylinder 44. A compression spring 52, locatedin the delivery passage 45 and disposed between the fitting 14 and theouter end of the valve member 46, acts on this valve member tending toshift the same in a direction to cause closing movement of the valveplunger portion 50 in relation to the valve seat 41.

At a point adjacent its outer end, the axial passage 48 of the volumecontrol valve member 46 is provided with an internal annular valve seat53. The volume control valve member 46 is also provided with radialby-pass ports 54 adjacent this internal valve seat 53 and which arecontinuously in communication with the valve chamber portion 39 Thepressure relief valve member 47 is slidable in the outer end portion ofthe axial passage 48 of the valve member 46 and includes a valve plungerportion 55 which cooperates with the internal annular valve seat 53,. Acompression spring 56 located in the axial passage 48 of the valvemember 46 acts on the pressure relief valve member 47 and urges the samein an outward direction to a position engaging the valve seat 53 forclosing the by-pass ports 54.

A spring ring 57 mounted in the valve member 46 retains the pressurerelief valve member 47 in the axial passage 48 and forms a stop againstwhich the pressure relief valve member is adapted to be held by thecompression spring 56. The pressure relief valve member 47 has an axialpassage 58 therein which includes a flow control orifice 59. The axialpassage 58 and the flow control orifice 59 connect the delivery passagewith the discharge port 27 through the axial passage 43 and the radialopenings 49 of the valve member 46.

The valve assembly 46) is more fully disclosed and claimed in copendingpatent application Serial No. 261,655, filed December 14, 1951, nowPatent 2,752,853, granted July 3, 1956. For the purposes of the presentinvention, it is sufficient to explain that the valve assembly 40 isresponsive to the pressure of the spring 52 and the fluid pressuredifferential across the orifice 59. When the pump 10 is being driven ata relatively high rate of speed, the resultant effect of these pressurescauses the valve assembly 40 to be shifted toward the left in oppositionto the spring 52 to thereby move the edge of the valve plunger portion50 past the shoulder 41* of the internal valve seat 41 to thereby causeopening of the volume control valve member 46 for by-passing pumpedfluid from the discharge port 27 to the by-pass passage 43 for return tothe intake side of the pump, The amount of fluid which is thus by-passedfor return to the intake side of the pump is dependent upon the extentof this opening movement of the valve member 46 and will be such thatthe rate at which pumped fluid will be supplied to the external fluidcircuit 12 through the delivery passage 45 will be automaticallymaintained at a desired substantially constant value.

The pressure relief valve member 47 is responsive to the pressure of thespring 56 and to the fluid pressures acting on opposite ends of thisvalve member. When the pump 10 is being operated at the relatively highspeed mentioned above, the resultant effect of these forces causes thepressure relief valve member 47 to be shifted towards the right inopposition to the spring 56 to cause an opening movement of the valveplunger portion relative to the bypass ports 54 for by-passing pumpedfluid from the delivery passage 45 to the by-pass passage 43 for returnto the intake side of the pump. The amount of fluid thus by-passedthrough the bypass ports 54 will depend upon the extent of this openingmovement of the pressure relief valve member 47 and will be such thatthe pressure of the fluid being supplied to the external fluid circuit12 will be automatically maintained at a desired substantially constantpressure value.

In accordance with the present invention, the pumped fluid which isby-passed through the passage 43 by the functioning of the valve members46 and 47 is returned to the intake side of the pump in a novel mannerwhich will now be described and by which turbulence in the intake fluidand noise resulting therefrom will be pre vented or kept at a minimum,and also by which the velocity of the by-passed fluid can be used toassist the flow of intake fluid to the intake port 24. The by-passpassage 43 accordingly extends between and connects the valve chamber 39and the intake passage 38.

In utilizing the by-passed fluid for the purposes just mentioned above,the present invention provides a flow directing means in the pumphousing 22 by which the bypassed fluid is directed along the intakepassage 38 in a donwstream direction, that is, toward the rotor chamber23. This flow directing means is preferably in the form of an insert 61located in the housing section 22 and extending axially in the intakepassage 38. The insert 61 is here shown as being an open-ended sheetmetal sleeve having a relatively tight engagement in the intake passage38 and whose upper end 61 communicates with the reservoir chamber 17.The lower end 61 extendstransversely of a junction port 62 located inthe side wall of the intake passage 38 and through which port the bypasspassage 43 communicates with the intake passage.

The lower end 61 of the insert extends at least partway across thejunction port 62 and cooperates with the side Wall of the intake passage38 in defining an annular space or pocket 63 whose lower end is incommunication with the intake passage and faces in the downstreamdirection of the latter, that is, opens toward the rotor chamber 23. Theportion of the insert 61 which is located opposite the junction port 62forms a deflecting means for the bypassed fluid entering the intakepassage 38 through the junction port, such that this by-passed fluidwill be deflected or directed toward the rotor chamber 23.

The by-passed fluid enters the intake passage 38 through the junctionport 62 as a velocity stream and when this velocity stream has beendeflected in the downstream direction by the insert 61, the energy ofthis by-passed fluid will be utilized in accelerating the flow of intakefluid toward the rotor chamber 23 through the passage 61 of the insertand through the intake passage 38. The walls of the intake passage 38are continuous throughout the portion of this passage extending from thejunction port 62 to the rotor chamber 23, such that the intake fluidwill be confined therein and the energy of the by-passed fluid will beutilized in creating a pressure head in this portion of the by-passpassage tending to accelerate the filling of the pumping chambers 35with a solid body of intake fluid.

When the by-passed fluid enters the intake passage 38 through the port62, it is desirable that the mingling or confluence of the stream ofby-passed fluid with the stream of intake fluid, take place with minimumdisturbance or noise-producing turbulence. To assist in achieving thisdesired result, the portion of the wall of the insert 61 locatedopposite the junction port 62, is shaped to constitute a deflector 64for facilitating a smooth mingling of the by-passed fluid with theintake fluid.

The deflector 64 is here shown as being an inwardly olfset transverselyconcave fluted portion or external indentation of the wall of the insert61. The transversely concave deflector portion 64, being locateddirectly opposite the port 62, will be eflective on the stream ofby-passed fluid to direct the same out of the pocket 63 and into theintake passage 38 in the above-mentioned downstream direction. Thefluted portion forming the deflecting means 64 can be shaped or drawn inthe side wall of the insert 61 by any suitable forming operation anddies.

From the foregoing detailed description and the accompanying drawings,it will now be readily understood that this invention provides novelflow directing means in a positive displacement rotary pump, and in apumping unit embodying such a rotary pump, by which fluid being bypassedfrom the discharge side of the pump to the intake side can be mingledsmoothly and with minimum turbulence and noise with the stream of intakefluid. Likewise, it will be seen that this novel flow directing meansalso provides for utilizing the by-passed fluid as a velocity stream forassisting the flow of intake fluid to the intake port for maintainingthe latter substantially filled at all times and preventing theformation of a vacuum or void condition therein, and for utilizing theenergy of the high velocity by-passed fluid for increasing the pressurehead of the intake fluid at points downstream from the junction point ofthe by-pass passage with the intake passage. Additionally, it will beunderstood that this flow directing means is employed in the form of anopen-ended insert sleeve mounted in the pump housing so as to extendalong the intake passage for a portion of the length thereof and withthe lower end portion of the insert cooperating with the by-pass passageas a deflecting means effective on the stream of by-passed fluid.

Although the flow directing means of this invention and the rotary pumpand pumping unit embodying the same have been illustrated and describedherein to a somewhat detailed extent, it will be understood, of course,that the invention is not to be regarded as being limitedcorrespondingly in scope but includes all changes and modificationscoming within the terms of the claims hereof.

Having thus described my invention, I claim;

1. In a rotary pump, a housing having therein a rotor chamber and intakeand discharge passages communicating with said rotor chamber, rotormeans operable in said rotor chamber for producing a pumping action,said housing also having a valve chamber communicating with thedischarge passage and a by-pass passage connecting said valve chamberwith the intake passage through a junction port, valve means in saidvalve chamber and operable to by-pass pumped fluid through said by-passpassage, said intake passage having a substantiallycontinuous side wallbetween the junction of said by-pass passage therewith and said rotorchamber for confining the fluid being supplied to said rotor chamber,and flow directing means comprising an insert sleeve extending alongsaid intake passage and having one end thereof extending transversely ofsaid junction port, a portion of the wall of said sleeve adjacent saidone end being oflset radially inwardly of the sleeve and forming adeflecting portion located substantially opposite said junction port.

2. In a rotary pump, a housing having therein a rotor chamber and intakeand discharge passages communicating with said rotor chamber, rotormeans operable in said rotor chamber for producing a pumping action,said housing also having a valve chamber communicating with thedischarge passage and a by-pass passage connecting said valve chamberwith the intake passage through a junction port, valve means in saidvalve chamber and operable to by-pass pumped fluid through said by-passpassage, said intake passage having a substantially continuous side wallbetween the junction of said by-pass passage therewith and said rotorchamber for confining the fluid being supplied to said rotor chamber,and flow directing means comprising an insert sleeve extending alongsaid intake passage and having a fluted portion disposed substantiallyopposite said junction port.

3. In a pumping unit of the character described, a housing havingtherein a rotor chamber and intake and discharge ports communicatingwith said rotor chamber, means defining a reservoir chamber supporteddirectly by said housing at an elevation above said rotor chamber, rotormeans operable in said rotor chamber for producing a pumping action,said housing also having in take passage means therein connecting saidreservoir chamber with said intake port for supplying fluid to thelatter, said intake passage means having a substantially continuous andimperforate side wall for confining in said intake passage means thefluid being supplied therethrough to said intake port, means forby-passing pumped fluid from said discharge port to said intake passagemeans including a by-pass passage communicating with said intake passagemeans through a junction port in the side wall of the latter, and flowdirecting means comprising an open-ended insert sleeve having itsupstream end relatively tightly engaged in said intake passage means andits downstream end extending at least part-way across said junction portand defining with said side wall an intervening pocket with which saidjunction port communicates and whose open end faces in the downstreamdirection of said intake passage means, the downstream end of saidinsert sleeve having a deflecting flute formed in the wall thereof andlocated substantially opposite said junction port.

4. In a pump and reservoir combination, a housing structure containing areservoir chamber and a rotor chamber provided with intake and dischargeports, said reservoir chamber being at an elevation above said rotorchamber, rotor means operable in said rotor chamber for the delivery ofpumped fluid through the discharge port, said housing structure alsohaving a permanently open intake passage connecting said reservoirchamber with the intake port and a passage for pumped fluidcommunicating with said intake passage through a permanently openjunction port located in the side Wall of the latter, and flow directingmeans comprising an insert sleeve located in and extending axially alongsaid intake passage, said sleeve having an open upstream end tightlyengaged in said intake passage and an axially open down stream endextending at least part-way across said junction port, said downstreamend having an external indentation in the side wall thereof, saidindentation being located substantially opposite to said junction portand defining with the side Wall of said intake passage an interveningpocket with which said junction port communicates and which pocket hasan open end communicating directly with said intake passage and facingin the downstream direction thereof.

5. A pump and reservoir combination as defined in claim 4 in which theupstream end of said insert is axially open and has a substantiallyuniform-size cylindrical shape above said indentation.

References Cited in the file of this patent UNITED STATES PATENTS MackJuly 13, Dunham Sept. 7, Staley Sept. 24, Davis Aug. 5, Moody July 31,Ruth July 9, Caserta Dec. 28, Jacobsen Apr. 12, Eames Nov. 22, HunterFeb. 7, Drude June 5,

FOREIGN PATENTS Great Britain June 13, Germany Aug. 17,

